One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(6,8)(9,10)(11,18)(12,16)(13,15)(14,17)(19,23)(20,22)(21,24)(25,26)(27,33)(28,34)(29,40)(30,35)(31,36)(32,37)(38,39) involution — undirected(9,11,14,13)(10,15,17,18)(12,20,21,19)(16,23,24,22)(25,27,32,30)(26,33,37,35)(28,36,38,29)(31,39,40,34)(1,2)(3,6)(4,5)(7,8)(25,28)(26,34)(27,29)(30,36)(31,35)(32,38)(33,40)(37,39) involution — undirected(3,7)(6,8)(9,12,14,21)(10,16,17,24)(11,19,13,20)(15,22,18,23)(25,29,32,36)(26,31,37,40)(27,38,30,28)(33,34,35,39)(1,3,4,7)(2,6,5,8)(9,10)(11,15)(12,16)(13,18)(14,17)(19,22)(20,23)(21,24)(25,30,32,27)(26,35,37,33)(28,36,38,29)(31,39,40,34)(1,2)(3,6)(4,5)(7,8)(9,13,14,11)(10,15,17,18)(12,20,21,19)(16,22,24,23)(25,31)(26,36)(27,39)(28,35)(29,37)(30,34)(32,40)(33,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.